A mounting device for securing plate-shaped elements (5) on a mounting rail (6) includes first (12; 52; 72) and second holding members (17; 57; 77) forming, together a space (16; 42) for receiving a plate-shaped element (5), a fastening member (27; 60) extending through the first (12; 52; 72) and the second (17; 57; 77) holding member and connectable with an anchoring element (23) provided on the mounting rail (6) for securing the mounting device (11; 41; 51; 71) on the mounting rail (6), and at least one resilient element (32; 46; 62; 92) provided between the first holding member (12; 52; 72), which is displaceable relative to the second holding member, and the second holding member (17; 57; 77) for spacing the first and second holding members (12, 17; 52, 57; 72, 77) from each other.